A buffer is one of many pieces that helps a rifle to operate normally. When a bullet is fired the energy that it released pushes a bolt carrier backwards which then connects with the buffer which typically works with a buffer spring located in a buffer tube. At the point of contact, the buffer pushes the spring backwards. Depending on the weight of the buffer and the strength of the spring the buffer will reconnect with the bolt carrier pushing a new bullet forward into the chamber to be fired. Buffer retaining pins should prevent movement of the buffer beyond the buffer retaining pin (also known as “detents”). Buffer retaining pins of the prior art typically have a protrusion atop thereof of circular cross-section area. Such pins can fail in use thereby deleteriously affecting correct operation of the rifle.
More recently, a heavy duty buffer retaining pin invented by Paul Leitner-Wise has come onto the market. This buffer retaining pin (shown in FIGS. 16-17) offers greater reliability and resistance to mechanical stress than retaining pins having a circular cross-section. But for reasons described below even these improved buffer retaining pins create issues due to lack of effective contact surface area upon contact with a buffer. Therefore, there remains a need for a better buffer retaining pin.